Rhodocybe pulchrisperma (Entolomataceae): A new species from North America

Brittonia, 37(2), 1985, pp. 182-185. © 1985, by the New York Botanical Garden, Bronx, NY 10458

RHODOCYBE P U L C H R I S P E R M A (ENTOLOMATACEAE): A NEW SPECIES F R O M N O R T H AMERICA RoY E. HALLINGAND TIMOTHY J. BARONI HaUing, Roy E. (New York Botanical Garden, Bronx, NY 10458-9980) and Timothy J. Baroni (Department of Biological Sciences, State University College, Cortland, NY 13045). Rhodocybepulchrisperma (Entolomataceae): A new species from North America. Brittonia 37: 182-185. 1985.--Rhodocybe lmlchrisperma is described as a new species of Agaricales from North America. It belongs in section Rhodocybe due to the brightly colored pseudocystidia and lack of clamp connections. The very large, handsomely ornamented basidiospores distinguish this species from others in the section. A key to taxa from Florida, Papua New Guinea, and India that exhibit similar features is presented.

An undescribed species of Rhodocybe was collected in Massachusetts. This unusual agaric is one more to be added to the 25 new taxa described in the genus recently (Horak, 1978, 1979, 1980; Noordeloos, 1979; Baroni, 1981). The new species, Rhodocybe pulchrisperma, poses an interesting phylogenetic problem in the genus because there are disjunct populations of apparently closely related species. In the description below, all microscopic features were observed or measured as revived in 3% KOH. The length of the basidiospores includes the hilar appendix; the length of basidia excludes the sterigmata. Drawings were made with the aid of a drawing tube. Color notations were taken from Kornerup and Wanscher (1978), e.g., 5A3, and color names are expressed as general approximations.

Rhodocybe pulchrisperma Baroni & Hailing, sp. nov. (Figs. 1-6) Pileus parvus, 10-16 mm latus, convexusvel depressus, glaber, atrobrnnneus, hygrophanus.LameUaeadnatae,emarginataevel sinuatae,crebrae vel subdistantes.Stipesbrunneusvel luteobrnnneus, + aequalis, siccus,infra mediumvestitus. Basidiosporaeinsolite magnae, 12-15 x 6-7 ~m, undique conspicueundulato-pusttdatae.Contentapseudocystidiorumlaeticolorata.Hyphaepileipellisrepentes, intertextae, pigmentoincrustantihullo, pilocystidiisinterdum erectis dispersis. Caulocystidiaad apicem stipitis orientia. Hyphaefibulisdestitutae. Odor nuUus. Sapor levitor ingratus sed non idiosyncraticus. Holotypusa D. H. Pfisterlectus (Halling3372) in herbario Farlowiano(FH) conservatus.

Pileus dark brown (7F8) overall at first, hygrophanous and fading to pale brown (5A4; 5B4; 5B5) with loss of moisture; 10-16 m m broad, convex to depressed on the disc, glabrous; margin slightly incurved, opaque at first, becoming striatulate; context thin, near pale orange (5A2) to watery brownish. Odor none. Taste slightly unpleasant but not distinctive. Lamellae adnate to emarginate or sinuate, to 3 m m broad, close to subdistant, edges even, 2-3 tiers of lamellulae; sordid orangish (5A3; 5B3) at first; edges concolorous. Stipe brown (6E8) to yellowish brown (5E8) with a whitish vesture of fibrils covering the lower 1/4 to 1/3; 20-40 m m long, apex 4-6 m m thick, _ equal or tapering downwards, generally terete, some compressed and then furrowed; surface dry, silky-shiny, +_ pruinose over the apex; fibrous-tough, hollow. Basidiospores pale orange (5A2; 6A2) to pale pinkish (7A2) in deposit, 12-15 (16.5) x 6-7/~m, amygdaliform, ellipsoid or subfusiform in lateral views, angular in polar view, strongly undulate-pustulate in all views; walls of immature spores strongly cyanophilic, mature ones weakly cyanophilic, inamyloid, pale yellowish in KOH. Basidia 35-43 x 8-10/~m, 4-sterigmate, clavate, lacking cyanophilic and siderophilic bodies; thin- or thick-walled, the latter not infrequent. Cheilocystidia and pleurocystidia (pseudocystidia) similar, 37-60 x 4-7 ~tm, thin walled,

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Fie. 1. Basidioearpsof Rhodocybepulchrisperma (Hailing 3372), x 2.

mostly cylindric to tapered cylindric to subfusoid or narrowly ventricose rostrate, abundant, arising from the subhymenium or trama, projecting up to 20 #m beyond the hymenium; contents dark golden and mostly granular in KOH. Lamellar trama of parallel, tightly compact, cylindric hyphae, 3-8 #m in diam. Pileal context of interwoven, cylindric hyphae, 3-8 #m in diam, not encrusted. Pileipellis a thin, hyaline or _ golden-colored layer in KOH, not well-differentiated from the context; hyphae repent, interwoven, cylindric, 3-7 #m in diam, occasionally with erect, pilocystidiate end cells. Pilocystidia widely scattered to _ infrequent, versiform, 20-40 x 3-5 #m, hyaline, not encrusted. Stipitipellis a compact layer of repent, parallel, cylindric hyphae, 2-4 #m in diam, producing caulocystidia at the apex. Caulocystidia consisting of loosely interwoven, ascending end cells, 3785 x 2-5 #m, mostly cylindric, sometimes subcapitate or sparingly branched near the apex, with pale golden-yellow, amorphous content in KOH. Clamp connections absent. Gregarious on soil in perennial flower bed. August. TYPE: U N I T E D STATES. MASSACHUSETTS. Middlesex Co.: Arlington, Claremont Street, 4 Aug 1981, Hailing 3372 (leg. D. H. Pfister) (HOLOTYPE:FH; ISOTYPE:

NY). Rhodocybe pulchrisperma belongs in section Rhodocybe due to the brightly colored hymenial pseudocystidia and the lack of clamp connections. The species can be distinguished from others in the section by its very large basidiospores (the largest known in the genus), the highly developed ornamentation of the

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FIGS. 2--6, Microscopic characters of Rhodocybepulchrisperma (Hailing 3372). 2. Pseudocystidia. 3. Basidia, thick-walled one at far fight. 4. Basidiospores. 5. Pilocystidia. 6. Section of stipitipellis at stipe apex showing cauloeystidia.

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b a s i d i o s p o r e surface, the small, h y g r o p h a n o u s pileus w i t h b r o w n i s h colors, a n d the a b s e n c e o f e n c r u s t i n g p i g m e n t s in the pileipellis. Presently there are only a few species in R h o d o c y b e t h a t possess large (longer t h a n 8 - 1 0 gm), strongly u n d u l a t e - p u s t u l a t e spores. T h e y are d i s t i n g u i s h e d in the following artificial key. K e y to l a r g e - s p o r e d species o f R h o d o c y b e 1 Pileus conic to campanulate, glabrous; odor not distinctive; encrusting pigment present on hyphae of pileipellis; clamp connections present; Papua New Guinea ............... R. gibbosa Horak 1 Pileus convex or convex-papillate or depressed on the disc, glabrous or villose-tomentose; odor absent, unpleasant, or of anise; encrusting pigment absent; clamp connections absent. 2 Pileus greater than 30 mm broad, glabrous, convex to broadly umbonate; odor of anise; pseudocystidia sometimes septate, unbranched; Florida, U.S.A.. R. atrigilva (Mutt.) Baroni 2 Pileus 30 mm broad or less, glabrous and convex to depressed, or villose-tomentose and with a distinct papillate umbo; odor strong and unpleasant or absent; pseudocystidia non-septate, sometimes branched. 3 Pileus 15-30 mm broad, convex with distinct papillate umbo, villose-tomentose, not hygrophanous; hyphae of pileipcllis forming a palisade or trichodermium; pseudocystidia sometimes forked; Sikkim, India ........................................................................ R. villosa Horak 3 Pileus 10-16 mm broad, convex to depressed, glabrous, hygrophanous; hyphae of pileipellis repent and interwoven, occasionally with erect pilocystidiate end cells; pseudocystidia not forked; Massachusetts, U.S.A ................................................................... R. pulchrisperma T h e presence o f brightly c o l o r e d p s e u d o c y s t i d i a c o m b i n e d w i t h the u n u s u a l l y large a n d highly o r n a m e n t e d b a s i d i o s p o r e s suggests close affinities a m o n g these four species, h o w e v e r , as i n d i c a t e d in the key, they o c c u r in w i d e l y separated localities. I f t h e y are closely related, the b r o a d d i s t r i b u t i o n o f these species raises q u e s t i o n s c o n c e r n i n g their m y c o g e o g r a p h y (Baroni, 1981). W e suspect t h a t the g r o u p is n o t relictual, b u t t h a t f u r t h e r e x p l o r a t i o n o f tropical a n d t e m p e r a t e S o u t h A m e r i c a will reveal m o r e taxa possessing the c o m b i n a t i o n o f p s e u d o c y s t i d i a a n d large, o r n a m e n t e d basidiospores.

Acknowledgments W e t h a n k R u p e r t B a r n e b y for correcting the L a t i n diagnosis, a n d Delia B a r o n i for p r o d u c i n g the b l a c k a n d white prints. A p o r t i o n o f this w o r k was c o m p l e t e d while the senior a u t h o r was a M u s e u m I n t e r n f u n d e d b y the N a t i o n a l M u s e u m A c t G r a n t F C - 3 0 5 8 1 7 to the N e w Y o r k Botanical G a r d e n .

Literature Cited Baroni, T.J. 1981. A revision of the genus Rhodocybe Maire (Agaricales). Beih. Nova Hedwigia 67: 1-194. Horak, E. 1978 [1979]. Notes on Rhodocybe Maire. Sydowia 31: 58-80• • 1979. Fungi agadcini Novazelandiae. VII. Rhodocybe Maire. New Zealand J. Bot. 17: 257281. • 1980. Indian Boletales and Agaricales. Revisions and new taxa. Sydowia 33:88-110. Kornerup, A. & J. H. Wanscher. 1978. Methuen handbook ofcolour. Ed. 3. E. Methuen, London. Noordeloos, M. E. 1979. A new species of Rhodocybe (Basidiomycetes, Agaricales) from north Norway. Norwegian J. Bot. 26: 277-278•